Merge bitcoin#17124: test: speed up wallet_address_types by whitelisting peers (immediate tx relay)

fba4baa test: speed up wallet_address_types by whitelisting peers (immediate tx relay) (Sebastian Falbesoner)

Pull request description:

  approaches another part of bitcoin#16613 ("Functional test suite bottlenecks")

  As for `wallet_backup.py` (Commit 581c9be), the
  bottleneck is in relaying transactions. By whitelisting the peers, the
  inventory is transmissioned immediately rather than on average every 5 seconds,
  speeding up the test significantly:

  before:
  ```
  $ time ./wallet_address_types.py
  real    1m30.072s
  user    0m6.478s
  sys     0m2.298s
  ```

  with this PR:
  ```
  $ time ./wallet_address_types.py
  real    0m26.785s
  user    0m5.525s
  sys     0m1.888s
  ```

ACKs for top commit:
  fanquake:
    ACK - fba4baa

Tree-SHA512: 6728ae44bd8839426fa943d06af884e40c2d88de5d7807269a1e78ff987077160aa7e8d395f4468e6ca1d6f2110c7a03cd346a3339b256702f4cdabd285f7f86

Author: MarcoFalke

test/functional/wallet_address_types.py

@@ -80,6 +80,9 @@ def set_test_params(self):
             ["-changetype=p2sh-segwit"],
             [],
         ]
+        # whitelist all peers to speed up tx relay / mempool sync
+        for args in self.extra_args:
+            args.append("-whitelist=127.0.0.1")
 
     def skip_test_if_missing_module(self):
         self.skip_if_no_wallet()